1. By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power.The saving in case of a double acting reciprocating pump is
2. Power required (in watts) to drive a centrifugal pump is (where Hm = Manometric head in metres, w = Specific weight in N/m3, Q = Discharge of the pump in m3/s, and ?o = Overall efficiency of the pump)